Conventionally, there is a liquid level detection device which has a sensor adhered on the outer surface of a container that contains liquid so that the liquid level position in the container can be detected (for example, see Patent Literature 1).
The liquid level detection device described in Patent Literature 1 includes a sensor body in a strip shape which is formed of a stack of a temperature measurement layer for measuring the temperature on the surface of the container and a heating layer for heating the container. When in use, the sensor body is adhered on the outer surface of the container with the longitudinal direction being oriented in the up and down direction of the container and the temperature measurement layer being located on the container side. The heat of the heating layer reaches the surface of the container via the temperature measurement layer, and due to this heat and the difference in heat transfer coefficient of the gas/liquid in the container, difference in temperature is generated between a portion of the temperature measurement layer which corresponds to the liquid in the container and a portion which corresponds to the gas in the container. Accordingly, the liquid level position is detected by using this difference in temperature in Patent Literature 1.
Further, as an installation method to the container, there is a magnet attraction device that allows an attraction surface of the liquid level detection sensor which uses ultrasonic wave to be brought into close contact with the container (for example, see Patent Literature 2).